Hose bibs are generally installed in outside building walls as a controlled source of water supply for garden hoses or the like. Such hoses attached to a hose bib often lie with their downstream ends in pools of muddy water which are often contaminated by chemical sprays, fertilizers and other poisonous materials, or are left dangling in swimming pools or various other receptacles. If the main water pressure from the source drops to form a vacuum or a sufficient back pressure develops, the contaminated or chemical laden water is sucked or forced backwardly into the pure water supply system, resulting in a health hazard to the users of water from the supply system.
This problem is well known in the plumbing art and a number of prior are patents disclose devices which attempt to circumvent it. U.S. Pat. Nos. 3,906,987 to Aushforth, et al., and 4,117,856 to Carlson disclose very complicated cross-connection valves for use in a main water supply conduit and provide no direct garden hose connection. Both of these devices are quite complex, utilizing pluralities of individual valving means and springs, making them not only costly to produce but they would appear to be unreliable due to their complexity. U.S. Pat. No. 2,037,023 to F. A. Holly illustrates a siphon breaker for interposition in the discharge line of a tank truck and includes a single movable flap which is pressure operated from a closed position relative to the discharge line to a closed position relative to a vent diring a discharging operation. This device is intended to combat a siphoning through the device only, a back pressure obviously not being encountered.
U.S. Pat. Nos. 3,416,556 to A. B. Nelson, 2,927,598 to W. Van E. Thompson and 3,454,032 to W. W. Hinz, et al., concern relatively complicated anti-backflow and vacuum breaker valves which are quite similar to the foregoing insofar as they incorporate floating, generally drum type valves. These valves operate on vertical guide means to vent or discharge flow fluids to the outside through top opening vents.
U.S. Pat. No. 3,565,097 to Robert B. Costa also employe a vertically slidable valve on a vertical post and operates in a manner quite similar to the three preceding discussed patents.
U.S. Pat. No. 3,424,188 to W. C. Whitaker, et al., discloses a faucet including a pop-up valve which responds vertically to supply line pressure to open and permit a discharge of water from the faucet. When a reduction of pressure occurs within the supply line so that the pressure in the faucet is less than atmospheric pressure, the pop-up element moves downwardly permitting an air flow into the faucet to break the vacuum in the supply line.
None of the above patents provide a positive interlock between a main check valve and a relief valve to insure a simultaneous operation thereof and eliminating partial or delayed operation of one of two valve means involved.
The present invention concerns a faucet such as a hose bib, which is particularly adapted for connection to a garden hose, and provides a very simplified valve means, utilizing no springs, in the form of a pair of interlocked flap valves which coact to permit a flow of pressurized water from a source through a supply conduit to the hose through the hose bib, with a control handle in an open position; and to divert a backflow of water from the hose to the faucet through a relief port in the faucet for outside discharge.
Therefore, one of the principal objects of the present invention is to provide a faucet such as a hose bib with a simplified valve means in the form of a pair of interlocked flap valves which coact to direct a flow of pressurized water from a source to a garden hose, for example, in first positions, and react to back pressures from the hose or negative pressures in the source, to second positions to close relative to the source and open relative to a relief port for outside discharge of any backflow from the hose.
A further object of the invention is to provide manual control means such as a handle to selectively secure said valves in said first positions, or permit said valves to be pressure operated to the second positions.
Other objects and advantages will become apparent to those skilled in the art upon reading the following descriptions and upon reference to the drawings.